A few people who've commented, here or by e-mail, admitted that they had the same reaction I did: "That doesn't say 'Nazi,' does it?" Some have tried to come up with alternative readings, but I'm not buying it.
Most states have requirements that personalized plates not be offensive, vulgar; some even limit political speech. Is this something that should be questioned officially? That's my question: do I go to the DMV and say "this license plate should be investigated and probably revoked" or do I just shrug and move on?